A vehicle bumper is fixed to a body panel via a retainer, and the retainer is fixed to the body panel using a clip. For example, in Japanese Patent Application Laid-Open (JP-A) No. 2006-125571 there is a clip configured with a grommet and pin, a sack body of the grommet is inserted into attachment holes formed in the body panel and the retainer, respectively, and after the body panel and the retainer are nipped between a flange portion and a claw portion formed at the grommet, the pin is inserted into the sack body. The amount of widening of the claw portion alone is increased by the pin pressing against the inside of the claw portion and widening the claw portion, and the retaining force of the retainer to the body panel is increased.
However, in Japanese Patent Application Laid-Open (JP-A) No. 2006-125571, when the claw portion engages with the pin, after the claw portion has been widened once (to the maximum widening amount), engagement is made with a smaller diameter step portion formed on the outer face of the pin. In the state in which the claw portion is engaged with the step, the widening amount of the claw portion is less than the maximum widening amount.
In other words, in order to raise the retaining force of the clip without changing the insertion force of the pin, a method of making the step smaller might be considered, since the closer the widening amount of the claw portion in the state of engagement with the step to approaches the maximum widening amount the better. However if the step is made smaller, then the click sensation when the claw portion engages with the step becomes less discernable.